Hydride Anion Substitution Boosts Thermoelectric Performance of Polycrystalline SrTiO3 via Simultaneous Realization of Reduced Thermal Conductivity and High Electronic Conductivity
Year: 2023
Type: article
Abstract: The development of environmentally benign thermoelectric materials with high energy conversion efficiency (ZT) continues to be a long‐standing challenge. So far, high ZT has been achieved using heavy elements to reduce lattice thermal conductivity (κlat). However, it is not preferred to use such elements because of their environmental load and high material cost. Here a new approach utilizing hydride anion (H−) substitution to oxide ion is proposed for ZT enhancement in thermoelectric oxide SrTiO3 bulk polycrystals. Light element H− substitution largely reduces κlat from 8.2 W/(mK) of SrTiO3 to 3.5 W/(mK) for SrTiO3−xHx with x = 0.216. The mass difference effect on phonon scattering is small in the SrTiO3−xHx, while local structure distortion arising from the distributed Ti−(O,H) bond lengths strongly enhances phonon scattering. The polycrystalline SrTiO3−xHx shows high electronic conductivity comparable to La‐doped SrTiO3 single crystal because the H− substitution does not form a grain boundary potential barrier and thus suppresses electron scattering. As a consequence, SrTiO3−xHx bulk exhibits maximum ZT = 0.11 at room temperature and the ZT value increases continuously up to 0.22 at T = 657 K. The H− substitution idea offers a new approach for ZT enhancement in thermoelectric materials without utilizing heavy elements.
Source: Advanced Functional Materials
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $5,250
Awards: Thermal conductivity switching by electric-field induced 2D-3D structural phase transition, Synthesis of novel materials in an electronically-stimulated nanogap, Construction of innovatively novel optical semiconductors based on the original chemical design concept, and evolution of their devices, Atomic-scale structural analysis of nanodevices under actual working environment, Mixed-anion thermoelectric oxides: performance enhancement by thermal conductivity reduction and mechanistic insights, G4137340833, G4636866504, G4703715196, Exploration of angular momentum current science and its application to spin-orbit electronics, Investigation of thermal and optical properties of perovskite materials by advanced phonon calculations, 水素と親和性の高い金属間化合物電子化物の探索：軟らかさからの新アプロ-チ
OpenAlex ID: W4366284759